WO2020020746A1 - Filter insert for exchangeable installation in a filter housing of a filter for fluid, and filter - Google Patents

Abstract

The invention relates to a filter insert (20) for exchangeable installation in a filter housing (14) of a filter (10) for fluid, and to a filter. The filter insert (20) comprises at least one filter medium (48) which at least partially delimits an insert interior (46) and through which the fluid for filtering can flow in the direction from or into the insert interior (46). The insert interior (46) has a fluid opening through which fluid can pass into or out of the insert interior (46), depending on the flow direction. The filter insert (20) also comprises a rigid connection frame (40) which protrudes radially from the insert fluid passage (42), axially outside the insert interior (46), and which is mechanically connected directly or indirectly to the at least one filter medium (42) and which surrounds an insert fluid passage (42) for the fluid continuously around an imaginary axis (22). The filter insert (20) can be fastened in the filter housing (14) with the aid of the connection frame (40) such that the insert fluid passage (42) is fluidically connected to a housing fluid passage (24) of the filter housing (14). The connection frame (40) is covered, at the end face thereof facing axially away from the at least one filter medium (48) in relation to the axis (22), in a planar manner with a flexible application medium (50) which continuously surrounds the circumference of the insert fluid passage (42) in a planar manner.

Description

 Filter insert for exchangeable installation in a filter housing

 a filter for fluid and filter

 Technical field

 The invention relates to a filter insert for replaceable installation in a filter housing of a filter for fluid,

 - With at least one filter medium, which at least partially delimits an insert interior and through which the fluid for cleaning can flow in the direction from or into the insert interior, the insert interior having a fluid opening through which, depending on the direction of flow, fluid flows into can get inside or out of the insert,

 with a rigid connection frame which is mechanically connected directly or indirectly to the at least one filter medium and which surrounds an insert fluid passage for the fluid in a circumferentially continuous manner with respect to an imaginary axis,

- The insert fluid passage is fluidly connected to the fluid opening of the insert interior

 - And wherein the filter insert can be fastened in the filter housing with the aid of the connection frame in such a way that the insert fluid passage is in fluid communication with a housing fluid passage of the filter housing.

The invention further relates to a filter for fluid, which has an openable filter housing,

 the filter housing has at least one housing fluid passage for introducing fluid to be cleaned into the filter housing and at least one housing fluid passage for discharging cleaned fluid from the filter housing,

 and at least one filter insert is interchangeably arranged in the filter housing in such a way that it separates the housing fluid passage for fluid to be cleaned and the housing fluid passage for cleaned fluid.

- The filter housing is composed of at least two separable housing parts, of which a first housing part has at least one housing fluid passage, which is fluidically connected to an insert fluid passage of the filter insert when the filter insert is installed, and the first housing part on the inside of the housing has a housing contact surface for direct or indirect investment of a connection frame of the at least one filter insert, the housing contact surface surrounding the housing fluid passage in a circumferentially continuous manner with respect to an imaginary axis

 - And wherein an installation direction of the at least one filter insert in the first Fil tergehäuse runs perpendicular to the axis in an assembly direction of the housing parts.

 State of the art

 A filter insert is known from DE 10 2010 047 491 A1, which comprises a filter element with an inlet-side end surface and an outlet-side end surface spaced from it in the flow direction and a frame running around the side surfaces of the filter element and connected to the filter element. The frame carries an axial seal, the sealing direction of which is oriented in or against the main flow direction. The seal can be brought into contact with a sealing surface of a filter housing in the sealing direction, as a result of which the inlet side of the filter insert can be sealingly separated from the outlet side. On two opposite side surfaces of the filter insert, the frame has a first and a second contact surface for bracing the filter element by means of a first or a second bracing element. The contact surfaces are oriented essentially opposite to the sealing direction. The contact surfaces each have an individual height profile running along the side surfaces.

The invention is based on the object of designing a filter insert and a filter of the type mentioned at the outset, with which attachment of the filter insert in the filter housing can be improved.

Disclosure of the invention

In the case of the filter insert, this object is achieved according to the invention in that the connection frame, on its end face axially facing away from the at least one filter medium with respect to the axis, is covered over a large area, in particular over the full area, with a flexible contact medium which covers the entire area of the insert fluid passage hanging surrounding. The occupied end face of the connection frame is provided by a section of the connection frame which lies axially outside the insert interior and projects radially beyond the insert fluid passage. The lead frame is thus clearly axially spaced from the interior of the insert and enables axial sealing. The system medium can be detachable, for example plugged on, or permanently connected to the connection frame, for example glued, welded, molded, molded. According to the invention, a guide function and a holding function are fulfilled with the aid of the rigid connection frame. In addition, tolerance compensation and / or a sealing function can be fulfilled with the flexible system medium. Overall, the attachment of the filter insert in the filter housing can be improved. The filter medium forms a filter medium body that at least partially limits the interior of the insert.

According to a preferred development, the connection frame can be designed to be at least uniaxially curved or kinked, preferably about an axis normal to the axis which corresponds to a main flow direction in a user arrangement. The curvature of the lead frame is recorded on the housing side in the form of a corresponding curvature of the housing contact surface in order to obtain a suitable interface pairing. A complex curved interface geometry can also be securely sealed with a fluid-permeable flat installation medium. A variation of the mutual radii of curvature can in particular also be used to assign filter insert types to housing types in order to avoid incorrect installation of unsuitable and / or non-original filter inserts.

According to a very particularly preferred embodiment of the invention, the investment medium is a fluid-permeable or fluid-flowable investment medium which has self-filtering properties. In this case, the installation medium suitably has a degree of separation in the installed state, which is above the degree of separation of the “actual” filter medium of the filter insert. For example, the degree of separation of the system medium when installed can be over 99.4%, although the invention is expressly not limited to this. In the following, however, the term “sealing effect” is also used in relation to fluid-permeable system media, although strictly speaking these could correctly be called sealing interface elements.

The system medium is arranged on the front side of the connection frame in such a way that it has a predetermined minimum width surrounding the insert fluid passage. The minimum width is at least 2 mm, values above 6 mm being preferred in order to achieve a good "sealing effect". In order to improve the attachment of the installation medium on the end face of the connection frame, at least one holding needle, preferably a plurality of holding needles distributed over the surface, can extend from the end side of the connection frame and drill into the installation medium to fix it. As an alternative or in addition, an annular collar, which at least partially surrounds the insert fluid passage, can extend from the end face of the connection frame, which supports the system medium and ensures, in particular during the installation process in a filter housing, that the system medium remains securely fastened. In some versions, the collar can also completely surround the insert fluid passage.

The connection frame can have a rectangular, in particular square, outer cross-section, it being possible in particular to provide for this cross-section to be covered over the entire area with the installation medium, so that the installation medium also has a rectangular outer cross-sectional contour.

The fluidic connection of the insert fluid passage to the fluid opening of the insert interior can take place indirectly or directly, in particular a spacing of the connection frame from the filter medium or filter medium body is provided. The fluidic connection can be provided, for example, by a piece of pipe that connects the insert fluid passage to the insert interior.

The connection frame and the system medium extend across the entire surface with respect to the axis. In this way, a flat contact of the investment medium on a corresponding housing contact surface is made possible. In this way, both the guidance of the filter insert when installed in the filter housing and the positioning and mounting of the filter insert can be improved. With the help of the flexible investment medium, a flat tolerance compensation can take place. In this way, component, assembly and / or operational tolerances, for example due to vibrations or the like, can be better compensated for. Mechanical forces acting on the connection frame can be introduced more uniformly, so that the overall holding function can be improved. The connection frame according to the invention can be used to reduce the effects of force on the filter medium. The filter insert has an interior. The interior of the application borders at least one filter medium. The interior of the insert is fluidly connected to the insert fluid passage. In this way, depending on the direction of flow of the fluid in the filter, the fluid to be cleaned can pass through the insert fluid passage into the insert interior and flow from there through the at least one filter medium. When the flow direction is reversed, the fluid to be cleaned can flow through the at least one filter medium for cleaning and reach the interior of the insert. The cleaned fluid can leave the filter housing from the insert interior through the insert fluid passage and the housing fluid passage.

The filter insert can advantageously be designed as a double filter insert or as a hollow filter insert.

A double filter insert has two filter media, in particular in the form of filter bellows, which delimit an interior space on opposite sides. A double filter insert can be configured in a V-shape or cuboid.

A hollow filter insert is characterized by the fact that it has at least one interior space which is surrounded by filter medium. The fluid to be cleaned can flow through the filter medium from the outside to the inside of the insert or vice versa. The interior of the insert has a fluid passage to the outside, through which, depending on the direction of flow, the cleaned fluid can leave the interior of the insert or the fluid to be cleaned can get into it. The filter medium can surround the interior of the insert circumferentially with respect to an axis. The filter medium can be connected to an end body, in particular an end plate, on at least one end face that is axial with respect to the axis. At least one end body can have at least one passage opening for the interior of the insert. The end body can either be connected to the lead frame or at least form it.

A hollow filter insert can advantageously be a so-called round filter element with a round cross section, an oval round filter element with an oval cross section, a flat oval round filter element with a flattened oval cross section, a conical round filter element in which the round cross section is in tapered in the axial direction to a main axis, a conical-oval round filter element in which the oval cross-section in the axial direction is at least in the direction of a transverse axis tapered, a conical flat-oval round filter element in which the flat-oval cross-section tapers in the axial direction at least in the direction of a transverse axis, or a hollow filter insert with a different, in particular an angular, cross-section and / or a different axial cross-sectional profile in the direction of the axis of the hollow filter insert, act, for example, a hollow filter element with a U-shape, which has both sections that run parallel to the main axis and sections that run curved to this.

The filter medium which forms the filter medium body can advantageously be closed or open circumferentially with respect to the axis. The filter medium can in particular be star-shaped, preferably zigzag-shaped or wavy, folded or bent. The filter medium can also be unfolded or unbent.

The filter can advantageously be an air filter. The air filter can advantageously be part of an air intake tract of an internal combustion engine. It can be used to clean combustion air which is fed to the internal combustion engine. However, the invention is not restricted to an air filter of an air intake tract of an internal combustion engine of a motor vehicle. Rather, it can also be used in other types of air systems in motor vehicles. The air filter can also be an interior filter. The air filter can also be used outside of automotive engineering, particularly in industrial engines.

The invention can also be used in filters for cleaning different types of liquid or gaseous fluids, in particular oil, fuel, water, urea-water solution, compressor air or the like.

The invention can be used in motor vehicles, in particular passenger cars, trucks, buses, agricultural and / or construction vehicles, construction / agricultural machinery, compressors, industrial engines or other devices, in particular with internal combustion engines. The invention can be used in land, water and / or aircraft.

The filter insert can advantageously be designed in such a way that it is installed in an installation direction perpendicular to the axis in a housing part of the filter housing can. In this way, the connection frame can be pushed along approximately parallel to its axial end face along a corresponding housing contact surface of the filter housing.

In an advantageous embodiment, the connection frame can be configured on its side axially facing the at least one filter medium with a guide and / or bracing structure, along which at least one housing-side guide and / or bracing element is guided when the filter is assembled and / or with which the connection frame can be clamped in the filter housing with at least one housing-side guide and / or bracing element. In this way, when installing the connection frame with at least one corresponding housing-side guiding and / or bracing element with respect to the axis, it can be pressed and guided in the axial direction against a corresponding housing contact surface. If necessary, the lead frame can be clamped in the installed state with the aid of the guide and / or bracing structure in cooperation with at least one guide and / or bracing element on the housing. In this way, stable folding can be achieved. Furthermore, an axial sealing effect between the lead frame and the housing contact surface can be improved, in particular in the case of an “intermediate” installation medium. The guiding and / or bracing structure on the side of the connection frame which faces the at least one filter medium can in particular be formed by a wedge-shaped course of the surface of the connection frame inclined to a normal direction of the main flow direction. In particular, this wedge-shaped course can be realized by changing the wall thickness of the lead frame. An inclined surface of the lead frame is particularly suitable as a corresponding counter contact surface for the above. housing-side guide and / or bracing elements.

In a further advantageous embodiment, the connection frame can be connected to a central tube of the filter insert. In this way, forces for holding the filter insert in the filter housing can be transmitted between the lead frame and the center tube. The center tube can surround the interior of the filter insert circumferentially. The at least one filter medium can be attached to the center tube. In this way, the effect of folding forces on the at least one filter medium can be reduced. The mechanical stress of at least one Filter medium can be reduced in this way. In a preferred embodiment, the connection frame and the central tube are formed in one piece.

In a preferred embodiment it can be provided that the lead frame is curved on its end face facing away from the filter medium. Alternatively or additionally, the connection frame can be inclined with respect to a normal plane of the axis, which corresponds to the main flow direction in a user arrangement. It can further be provided that a longitudinal center axis of the insert fluid passage is arranged offset to the longitudinal center axis of the insert interior. The corresponding housing contact surface, on which the connecting frame is supported in a sealing manner in the user arrangement via the system medium, must be complementary.

The connecting frame can advantageously be realized in one piece or in several parts with the center tube. The connection frame and the center tube can be manufactured and assembled in one piece. Furthermore, a stable connection between the connection frame and the center tube can be realized. The connection frame and the center tube can be combined in several parts.

In a further advantageous embodiment, the system medium can perform a sealing function. In this way, a separate seal can be dispensed with.

In a further advantageous embodiment, the investment medium can be elastic. In this way, tolerance compensation can be improved. In addition, operational vibrations can be better compensated in this way.

In a further advantageous embodiment, the investment medium can comprise or consist of polyurethane, PUR foam, cellular rubber, rubber, in particular soft rubber, silicone, elastomers, nonwoven or a combination of several components or the like. In this way, an elasticity and a sealing effect of the investment medium can be improved.

According to a particularly preferred embodiment, it can be provided that the nonwoven medium has a thickness in a range from 3 to 10 mm, preferably 5 to 8 mm. The nonwoven investment medium must have a certain minimum thickness in order to to enable sufficient pressing in an assembled state and in particular also to be able to compensate for tolerances, in particular deviations in flatness in the plane of the end face of the lead frame.

As an alternative or in addition, an air permeability of the nonwoven medium according to DIN EN ISO 9237 at 200 Pa can be in a range from 500 to 2500 l / m ² s, preferably in a range from 1000 to 1600 l / m ² s (uncorrected values). The values corrected according to DIN EN ISO 9237 at 200 Pa for the influence of side air lie between 400 and 2400 l / m ² s, preferably between 850 and 1500 l / m ² s.

Alternatively or additionally, a weight per unit area can range from 200 to 800 g / m ² , preferably 300 to 600 g / m ² . It was surprisingly found that by means of nonwoven media, which are subject to the aforementioned parameter ranges, an arrangement can be created with a fluid medium through which the fluid can flow, which is characterized by a convincing "tightness" in the sense of a particle penetration lying under the actual filter medium distinguished.

According to another preferred development, the nonwoven medium can be a copolyester-polyester nonwoven, preferably PET / coPET, which particularly preferably has core-sheath bicomponent fibers. Alternatively, the nonwoven medium can be a pure polyester nonwoven, which is advantageous for improved temperature resistance, in particular temperature change resistance. When using a pure polyester fleece, in particular PET-based, operating temperatures above 150 ° C can be reached. However, the invention is not limited to the above-mentioned compositions, but expressly also encompasses other material compositions which appear suitable to the person skilled in the art, in particular non-woven materials made of polyolefin fibers, for example PP, PE. The use of such fleece media can even achieve a temperature resistance superior to that of classic PUR seals.

When using a nonwoven medium as the contact medium or sealing layer, there is an enormous cost advantage compared to classic PUR, EPDM or TPE sealing materials, which can be 30 to 70% depending on the design.

In a further advantageous embodiment, the system medium can be softer than the lead frame. In this way, mechanical stability can be excluded. lent through the lead frame. The tolerance compensation and / or the sealing effect can only take place via the system medium. The effect of the system medium and the connection frame can thus be improved. In the present case, soft is understood to mean a higher flexibility, ie a lower modulus of elasticity. This means that, compared to the connection frame, the system medium can be deformed with less force than the connection frame to fulfill its sealing function.

The object is further achieved according to the invention in the case of the filter in that the housing contact surface on the inside of the housing is at least partially surrounded by at least one positioning element such that the housing contact surface on its side facing an installation opening of the first housing part for the filter insert is freely accessible. In this way, a corresponding connection frame can be guided and held on the side of the filter insert with the at least one positioning element during installation. In this way, the filter insert can be better positioned in the filter housing. Furthermore, it can be avoided that an incorrect filter insert can be installed in the filter housing or a correct filter insert can be incorrectly installed in the filter housing. Overall, the functional reliability of the filter can be improved.

According to a preferred embodiment, the installation medium present on the end face of the connection frame of the filter insert can be compressed to an uncompressed initial thickness in an assembled state by 30 to 70%, preferably 40 to 60%. A reliable "seal" is achieved in particular through the use of a nonwoven medium as the investment medium. In order to achieve the above-described pressing, the installation medium is axially compressed by a predetermined amount between the housing contact surface and the lead frame. The “thickness” or the distance between the housing contact surface and the lead frame in the installed state for the system medium is also referred to as the chamber dimension. Depending on the above, the chamber dimensions can Degree of compression 1, 5 to 7 mm.

For installation, the at least one filter insert can initially be in an assembly direction perpendicular to the axis through a corresponding installation opening in the first housing. seteil be introduced. The second housing part can then be connected to the first housing part in the assembly direction in such a way that the installation opening is closed.

In an advantageous embodiment, a second housing part can have at least one guiding and / or bracing element which extends in the direction of assembly of the housing parts and which on the back of the connection frame of the filter insert, which faces away from the housing contact surface of the first housing part, attacks. In this way, the at least one guide and / or bracing element can slide along the rear of the connection frame of the filter insert when the housing parts are assembled and thus press the connection frame with respect to the axis in the axial direction against the housing contact surface. In this way, the holding function of the lead frame can be improved. Furthermore, any sealing function in the axial direction between the lead frame and the housing contact surface can be improved.

Furthermore, the at least one guiding and / or bracing element can interact with the at least one positioning element of the first housing part when assembling the housing parts. The at least one positioning element can engage on the side of the at least one guide and / or bracing element that faces axially away from the housing contact surface. In this way, the connection frame of the at least one filter insert can be axially clamped between the housing contact surface and the at least one guide and / or bracing element.

In a further advantageous embodiment, at least two sword-shaped guide and / or bracing elements can be arranged like a fork. In this way, the guide and / or bracing elements can engage on the connection frame of the filter insert from radially opposite sides with respect to the axis. In this way, the connection frame can be pressed more uniformly in the axial direction against the housing contact surface of the first housing part.

Otherwise, the features and advantages shown in connection with the filter insert according to the invention and the filter according to the invention and their respective advantageous embodiments apply mutually accordingly and vice versa. The A- Individual features and advantages can of course be combined with one another, whereby further advantageous effects can arise that go beyond the sum of the individual effects.

Brief description of the drawings

 Further advantages, features and details of the invention result from the following description, in which an embodiment of the invention is explained in more detail with reference to the drawing. The person skilled in the art will expediently also consider the features disclosed in combination in the drawing, the description and the claims in combination and combine them into useful further combinations. It shows schematically:

 Figure 1 is an exploded view of a filter for cleaning air, which one

 Filter housing with a housing pot and a housing cover, in which a filter insert is interchangeably arranged;

 FIG. 2 shows a top view of the opened filter from FIG. 1;

 3 shows a section through the opened filter from FIG. 2 in the area of a housing air outlet along a section line II-II there in an early installation phase of the filter insert in the housing pot;

 FIG. 4 shows a section of the illustration from FIG. 3 along the section line there

 IV - IV;

 5 shows the section corresponding to Figure 3 in a further installation phase, in which the

 About half of the filter insert is installed in the housing pot;

6 shows a section of the illustration from FIG. 5 along the section line there

 VI - VI;

 Figure 7 shows the section corresponding to Figures 2 and 5, the filter insert in its

 End position is shown in the housing pot;

 FIG. 8 shows a section of the illustration from FIG. 7 along the section line there

 VII - VII;

 FIG. 9 shows a longitudinal section of a filter insert,

 Figure 10 is an isometric view according to another embodiment of the filter insert (filter medium and system medium are not shown);

FIG. 11 shows an isometric view of the filter insert according to FIG. 10 with filter medium and system medium, FIG. 12 is an isometric view of a filter insert with filter medium and application medium and a curved connection frame.

In the figures, the same components are provided with the same reference symbols.

Embodiment (s) of the invention

 FIG. 1 shows an exploded view of a filter 10 for cleaning fluid. FIG. 2 shows the opened filter 10 without the housing cover 12. The filter 10 can be used to clean air, for example combustion air for supply to an internal combustion engine, for example in a motor vehicle.

The filter 10 comprises a filter housing 14 with a housing pot 16, which has an installation opening 18 for a filter insert 20. The installation opening 18 can be closed with the housing cover 12.

The housing pot 16 has a housing air outlet 24 on an axial end face with respect to an imaginary axis 22, through which cleaned air can get out of the filter housing 24. The housing air outlet 24 is arranged, for example, coaxially with the axis 22.

If the term "axial", "radial", "coaxial", "circumferential" or the like is used below, this refers to the axis 22. When the filter 10 is mounted, the axis 22 corresponds to an axis of the filter insert 20.

In the same end face of the housing pot 16, a housing air inlet 26 is arranged next to the housing air outlet 24. Through the housing air inlet 26 to clean air can get into the filter housing 14.

The filter insert 20 is arranged in the filter housing 14 in such a way that it separates the housing air outlet 24 from the housing air inlet 26 in terms of air flow.

On the side axially facing the interior of the filter housing 14, the housing air outlet 24 is surrounded by a housing contact surface 28 in a continuous manner. The housing contact surface 28 is shown in particular in FIGS. 3 and 5. The housing contact surface 28 comprises a sealing zone 30 and a compensation zone 32. The sealing zone 30 surrounds the housing air inlet 26 in a ring shape. The compensation zone 32 is flat and surrounds the sealing zone 30 in a circumferential manner. An assembly direction 34 of the filter 10 runs perpendicular to the axis 22. In the assembly direction 34, the filter insert 20 is installed in the housing pot 16 and the housing cover 12 is mounted on the housing pot 16.

With respect to an imaginary plane, which is spanned by the assembly direction 34 and the axis 22, on opposite sides of the housing air outlet 24, two positioning webs 36 are arranged. The positioning webs 36 each have an approximately U-shaped profile, the openings of the "U" each facing the other positioning web 36. The positioning web 36 is in each case open on the side facing the installation opening 18. The positioning webs 36 are used to guide and position a rigid connection frame 40 of the filter insert 20.

The connection frame 40 surrounds an insert air outlet 42 of the filter insert 20 in a circumferential and flat manner. On an axial end face, the connecting frame 40 is connected in one piece to a central tube 44 of the filter insert 20.

The central tube 44 extends coaxially to the axis 22 and surrounds an insert interior 46 in a circumferentially continuous manner. The peripheral wall of the central tube 44 is permeable to air. Two blocks of filter medium 48 are arranged on the radially opposite circumferential sides of the central tube 44. The filter medium 48 can be, for example, filter fleece or another material suitable for filtering air. By way of example, the filter medium 48 can be folded in a zigzag shape to implement a block.

The center tube 44 has an overall conical shape. The diameter of the central tube 44 decreases from the connection frame 40 when viewed in the axial direction. Overall, the filter insert 20 is approximately V-shaped when viewed in the assembly direction 34. As is known, a filter insert 20 constructed in this way can be referred to as a “double bellows filter insert”.

On the end face facing away from the two filter media 48, the connection frame 40 is covered with an elastic, that is to say flexible, installation medium 50 over the entire surface. The system medium 50 can be made, for example, of polyurethane, polyurethane foam, rubber, cellular rubber, fleece or another correspondingly elastic material. stand. The system medium 50 can be realized with the lead frame 40 as a two-component component. The system medium 50 is softer than the rigid connection frame 40.

The system medium 50 has an insert sealing zone 52 which surrounds the inlet air outlet 42 in a ring shape. Furthermore, the system medium 50 has an insert compensation zone 54 which surrounds the insert sealing zone 52 in a coherent, circumferential manner. When the filter 10 is assembled, the insert sealing zone 52 lies in a sealing manner in the axial direction on the housing sealing zone 30. The application compensation zone 54 lies against the housing compensation zone 32 and ensures compensation of assembly and operational tolerances and vibrations.

The housing cover 12 has two sword-shaped guiding and bracing elements 56 on the axial end face, which faces the end face of the housing pot 16 with the housing air outlet 24 and the housing air inlet 26 when the filter 10 is mounted. The guide and bracing elements 56 each extend parallel to the assembly direction 34 on sides radially opposite one another with respect to the axis 22. The guide and bracing elements 56 are thus arranged in a fork-like manner overall. The distance between their radially facing outer sides is smaller than the distance between the positioning webs 36 of the housing pot 16. The guide and tensioning elements 56 can be guided in the positioning webs 36 when the filter housing 14 is assembled.

The guide and tensioning elements 56 are tapered towards their free ends.

To assemble the filter 10, the filter insert 20 is inserted into the housing pot 16 in the assembly direction 34 such that the connection frame 40 is guided between the positioning web 36.

The housing cover 12 is then mounted on the housing pot 16 in the direction of assembly 34, the guide and bracing elements 56, viewed axially, being guided between the positioning webs 36 of the housing pot 16 on the rear side of the connection frame 40 of the filter insert 20.

The rear side of the connecting frame 40 facing the interior of the housing pot 16 is equipped with a guide and bracing structure 57, on which the guide and tensioning elements 56 can slide along each. The rear side of the guide and bracing elements 56 is supported axially against the positioning webs 36 and press the connection frame 40 axially against the housing contact surface 28. The contact medium 50 becomes stronger in the area of the insert sealing zone 52 pressed than in the area of the insert compensation zone 54, so that an axial sealing effect is improved between the insert sealing zone 52 and the housing sealing zone 30. In the area of the insert compensation zone 54, the axial pressing is less, so that there corresponding oscillations and vibrations of the filter insert 20 can be compensated for relative to the housing pot 16, which also reduces the assembly forces.

In Figures 3 to 7 three phases are shown as an example when installing the filter insert 20 in the housing pot 16.

FIGS. 3 and 4 show a first phase in which the installation medium 50 is just outside the area of the housing contact surface 28. The lower edge of the housing contact surface 28, which faces the installation opening 18, is bent away from the housing interior and forms an insertion ramp 58 for the installation medium 50. The installation medium 50 is guided along the insertion ramp 58 when the filter insert 20 is installed.

FIGS. 5 and 6 show an installation phase of the filter insert 20, in which the lower area of the connection frame 40 and the contact medium 50 facing the lower edge is located within the area of the housing air outlet 24.

FIGS. 7 and 8 show the filter insert 20 in its end position, in which the connection frame 40 with the contact medium 50 lies completely against the housing contact surface 28.

When the filter is operating, air to be cleaned flows through the housing air inlet 26 into the filter housing 14. The area of the interior of the filter housing 14 surrounding the filter insert 20 forms a raw air side of the filter insert 20. The air flows through the filter media 48 from radially outside to radially inside, is cleaned there and reaches the interior 46. The interior 46 forms a clean air side of the filter insert. zes 20. The cleaned air flows from the insert interior 46 through the insert air outlet 42 into the housing air outlet 24 and leaves the filter housing 14 through this.

The filter insert 20 is shown on its own in FIG. The connection frame 40 and the central tube 44 can in this case be formed in particular in one piece. The connection frame has the contact medium 50 on its end face facing away from the filter medium 48 and has the guide and / or bracing structure 57 on the end face facing the filter medium, which structure is inclined, for example, by a plane normal to the longitudinal center axis 22 Can have course. The guide and / or bracing structure 57 can be used in a user arrangement, as already described herein, for better pressing the system medium 50, for which purpose a guide and / or bracing element on the housing can be used, which can be designed as a clamping wedge and causes compression in the axial direction , The spaced arrangement of connection frame 40 and filter medium 48 can also be clearly seen in the illustration, the spacing being achieved by a section of the insert fluid passage 42 which extends in the axial direction and which at one end breaks through the connection frame 40 and fluidly at the other end Insert interior 46 is connected.

A filter insert 20 according to a further embodiment is shown in FIGS. 10 and 11. For a better overview, the filter medium and the system medium are not shown in FIG. 10. A plurality of holding needles 43 extend axially from the front side of the connecting frame 40 and spread over its surface, which claw in the system medium 50 and hold it non-positively, so that it cannot slip, particularly when installed in a filter housing. Furthermore, a retaining collar 43 or annular collar, which partially encircles the insert fluid passage 42, extends from the end face of the connecting frame 40 in the axial direction and additionally fixes the system medium. The retaining collar 43 is suitably arranged on a front peripheral edge of the insert fluid passage 42 in the mounting direction.

According to this and further embodiments, the insert fluid passage 42 has an axial tube section 45, which fluidly connects the connection frame 50 to the insert interior 46 in the above-mentioned manner in the axial direction. Finally, a last embodiment of the filter insert 20 according to the invention is shown in FIG. 12. This differs from the embodiment shown in FIG. 11 in that the lead frame 40 is designed to be bent or kinked about an axis that is normal to the longitudinal direction, the angle of curvature being identified by a. The counter interface of the housing, that is to say the housing contact surface 28, suitably has a bend corresponding to the bend of the lead frame 40. When the preferably fluid-permeable, flat contact medium 50 provided according to the invention is used as the "seal", there are no problems, even reliably "sealing" jagged, curved, curved and / or kinked interface pairs.

Claims

Expectations  1. filter insert (20) for interchangeable installation in a filter housing (14) of a filter (10) for fluid,  - With at least one filter medium (48), which at least partially delimits an insert interior (46) and through which the fluid for cleaning can flow in the direction of the insert interior (46) or into the insert interior (46), the insert interior ( 46) has a fluid opening through which, depending on the direction of flow, fluid can get into or out of the insert interior (46),  - With a rigid connection frame (40) which is mechanically connected directly or indirectly to the at least one filter medium (48) and which surrounds an insert fluid passage (42) for the fluid with respect to an imaginary axis (22) in a circumferentially continuous manner , the axis (22) corresponding to a main flow direction in a usage arrangement,  - The insert fluid passage (42) is fluidly connected to the fluid opening of the insert interior (46)  - And wherein the filter insert (20) can be fastened in the filter housing (14) with the aid of the connection frame (40) in such a way that the insert fluid passage (42) with a housing fluid passage (24) of the filter housing (14) in terms of fluid technology Connection is established, characterized in that the connection frame (40) is arranged at a distance from the filter medium (48) and the connection frame (40) protrudes axially outside the insert interior (46) radially over the insert fluid passage (42) and on it at least one filter medium (48) with respect to the end face axially facing away from the axis (22) is covered with a flexible, preferably fluid-permeable, system medium (50) which surrounds the insert fluid passage (42) in a coherent, circumferential manner.  2. Filter insert according to claim 1, characterized in that the connection frame (40) is completely covered with the flexible system medium (50). 3. Filter insert according to claim 1 or 2, characterized in that the connection frame (40) is at least uniaxially curved or kinked, preferably about an axis normal to the axis (22), which corresponds to a fluff flow direction in a user arrangement. 4. Filter insert according to one of claims 1 to 3, characterized in that the connection frame (40) is configured on its side axially facing the at least one filter medium (48) with a guide and / or bracing structure (57) on which at least one housing-side guiding and / or bracing element (56) can be guided along when assembling the filter (10) and / or with which the connecting frame (40) with at least one housing-side guiding and / or bracing element (56) in the Filter housing (14) can be clamped.  5. Filter insert according to one of claims 1 to 4, characterized in that the connection frame (40) with a central tube (44) of the filter insert (20) is connected.  6. Filter insert according to one of claims 1 to 5, characterized in that the connection frame (40) is curved on its end face facing away from the filter medium (48) and / or the connection frame (40) with respect to a normal plane of the axis ( 22), which corresponds to the main flow direction in a user arrangement, is inclined.  7. Filter insert according to one of the preceding claims, characterized in that the system medium (50) fulfills a sealing function.  8. Filter insert according to one of the preceding claims, characterized in that the system medium (50) is elastic.  9. Filter insert according to one of the preceding claims, characterized in that the system medium (50) has or consists of polyurethane, PUR foam, cellular rubber, rubber or a combination of several components or the like.  10. Filter insert according to one of claims 1 to 8, characterized in that the fluid-permeable system medium (50) comprises or consists of a nonwoven medium, the fluid-permeable system medium (50) preferably having a higher particle separation rate than the filter medium (48).  11. Filter insert according to claim 10, characterized in that the nonwoven medium a thickness in a range from 3 to 10 mm, preferably 5 to 8 mm, and / or an air permeability according to DIN EN ISO 9237 at 200 Pa in a range from 500 to 2500 l / m ² s, preferably in a range from 1000 to 1600 l / m ² s, and / or - a weight per unit area in a range from 200 to 800 g / m ² , preferably 300 to 600 g / m ² ,  having.  12. Filter insert according to one of the preceding claims, characterized in that the system medium (50) is softer than the lead frame (40).  13. filter (10) for fluid, which has an openable filter housing (14),  - wherein the filter housing (14) has at least one housing fluid passage (26) for introducing fluid to be cleaned into the filter housing (14) and at least one housing fluid passage (24) for discharging cleaned fluid from the filter housing (14),  - And in the filter housing (14) at least one filter insert (20) is arranged interchangeably according to one of the preceding claims such that it has the housing fluid passage (26) for fluid to be cleaned and the housing fluid passage (24) for separates cleaned fluid from a fluidic point of view,  - The filter housing (14) is composed of at least two separable housing parts (12, 16), of which a first housing part (16) has at least one housing fluid passage (24), which has an insert fluid passage when the filter insert (20) is installed (42) of the filter insert (20) is fluidly connected, and the first housing part (16) has a housing contact surface (28) on the inside of the housing for direct or indirect contact of a connection frame (40) of the at least one filter insert (20), wherein the housing contact surface (28) surrounds the housing fluid passage (24) in a circumferentially continuous manner with respect to an imaginary axis (22)  - and wherein an installation direction of the at least one filter insert (20) in the first housing part (16) extends in an assembly direction (34) of the housing parts (12, 16) perpendicular to the axis (22),  characterized in that the housing contact surface (28) on the inside of the housing is at least partially surrounded by at least one positioning element (36) in such a way that the housing contact surface (28) on its one installation opening (18) of the first housing part (16) for the filter insert (20) facing side is freely accessible. 14. Filter according to claim 13, characterized in that the system medium (50) present on the end face of the connection frame (40) of the filter insert (20) 30 to 70%, preferably 40 to 60%, is pressed against an uncompressed initial thickness.  15. Filter according to claim 13 or 14, characterized in that a second housing part (12) has at least one guide and / or bracing element (56) which extends in the direction of assembly (34) of the housing parts (12, 16) and which engages on the rear side of the connection frame (40) of the filter insert (20), which faces away from the housing contact surface (28) of the first housing part (16).  16. Filter according to claim 15, characterized in that at least two sword-shaped guide and / or bracing elements (56) are arranged like a fork.